Conventionally, saturated carboxylic acid esters, such as ethyl acetate, n-propyl acetate, isobutyl acetate and n-butyl acetate, have been widely used as a solvent or a reaction solvent, and they are industrially important compounds.
These saturated carboxylic acid esters may be produced by a hydrogenation reaction of unsaturated carboxylic acid esters of corresponding chemical structures.
As the method for producing unsaturated carboxylic acid esters, there are several methods.
Specific examples thereof include a production method of an esterification reaction of unsaturated alcohol and carboxylic acid, and a production method of an oxidative carboxylation reaction using a carboxylic acid, oxygen and an olefin compound.
For example, the method for producing allyl acetate generally includes a method for producing allyl acetate by the esterification reaction of allyl alcohol and acetic acid or by the oxidative carboxylation reaction of propylene, acetic acid and oxygen.
In such an esterification reaction or oxidative carboxylation reaction, allyl acetate and water are simultaneously produced. For this reason, allyl acetate obtained by such a reaction generally contains water as a by-product and unreacted acetic acid as impurities. That is, industrially available allyl acetate is any of allyl acetate containing water, or allyl acetate from which water has been removed by a certain method.
For example, in the oxidative carboxylation reaction of propylene, acetic acid and oxygen, allyl acetate and water are produced, as shown in the Reaction Scheme below.

When unsaturated carboxylic acid esters are produced by the esterification reaction of unsaturated alcohol and carboxylic acid, generally, since there is a reaction equilibrium in the esterification reaction of unsaturated alcohol and carboxylic acid, unsaturated alcohol and carboxylic acid raw materials, in addition to the products of unsaturated carboxylic acid ester and water, also remain in the reaction mixture after reaching a steady-state. Therefore, when unsaturated carboxylic acid esters are subjected to a hydrogenation reaction, it is necessary to separate high-purity unsaturated carboxylic acid esters from the reaction mixture, after the esterification reaction of unsaturated alcohol and carboxylic acid.
On the other hand, as the method for producing unsaturated carboxylic acid esters by the oxidative carboxylation reaction using a carboxylic acid, oxygen and an olefin compound, Patent Citation 1 discloses a method for producing allyl acetate by the gas-phase reaction of propylene, oxygen and acetic acid in the presence of a palladium catalyst. According to this production method, it is stated that allyl acetate can be industrially produced advantageously.
However, unreacted carboxylic acid which is a raw material, in addition to unsaturated carboxylic acid ester which is the product of an oxidative carboxylation reaction and water, is frequently included in the mixture obtained from the reactor outlet. Therefore, when unsaturated carboxylic acid esters are subjected to a hydrogenation reaction, it is necessary to separate high-purity unsaturated carboxylic acid esters from the mixture obtained after the oxidative carboxylation reaction.
Further, when unsaturated carboxylic acid esters are subjected to a hydrogenation reaction, an isomerization reaction or hydrogenation decomposition reaction which is a minor reaction may be accompanied, in conjunction with a hydrogenation reaction which is a major reaction. For this reason, the hydrogenation reaction of unsaturated carboxylic acid esters is required to exhibit suppression of a minor reaction as much as possible.
Patent Citation 2 discloses a production method including subjecting unsaturated carboxylic acid ester to a hydrogenation reaction in the presence of a nickel-based hydrogenation catalyst, as the method for producing saturated carboxylic acid esters. According to this production method, it is believed that saturated carboxylic acid ester can be produced with a high yield by suppressing a hydrogenation decomposition reaction.